Burglar-alarm.



0. DE STEFANO.

BURGLAR ALARM.

7 APPLICATION FILED Main. 1911.

1,29%,2242 Patented Feb.11,1919.

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BURGLAR-ALABM.

Specification of Letters Patent.

Patented Feb. 11, 1919.

Application filed March 17, 1917. Serial No. 155,514.

To all whom it may concern:

Be it known that I, CHARLES DE STEFANO, a citizen of the United States, residing at North Bellport, in the county of Suffolk and State of New York, have invented certain new and useful Improvements in Burglar-Alarms; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a burglar alarm and has for one of its objects the provision of a device of this character, which may be readily applied to a window or door and upon opening the door or window,'the alarm will be operated, notifying the occupants of the house that an unauthorized person is in the act of entering.

Another object of the invention is to provide a base secured to the window or door frame and having means thereon adapted to be engaged by the door or window as it is opened to sound the alarm.

A further object of this invention is the provision of a spring actuated rod slidably mounted upon the base and having an arm pivoted thereto adapted to overlie the door or window for the purpose of rotating said rod to free the same when placed in a set position so that the rod when free will sound an alarm.

A still further object of this invention is the provision of a burglar alarm of the above stated character, which shall be simple, durable and efiicient, and which may be manufactured and sold at a comparatively low cost. y 7

With these and other objects in view as will become more apparent as the description proceeds,the invention consists of certain novel features of construction, combination and arrangement of parts as will be hereinafter more fully described and claimed.

For a complete understanding of my invention, reference is to be had to the following description and accompanying drawing, in which:

Figure 1 is a fragmentary front elevation of a door and a door frame, illustrating my invention applied thereto in several points,

Fig. 2 is a top plan view of a burglar alarm constructed in accordance with my invention,

Fig. 3 is a longitudinal sectional view of the same, taken on the line 3-3 of Fig. 1.

Fig. 4: is a transverse sectional view taken on the line H of Fig. 2.

Referring in detail to the drawing, the numeral 1 indicates as an entirety, a burglar alarm constructed in accordance with my invention and is adapted to be applied to a window frame or door frame and to more clearly illustrate my invention, I have shown the same applied to a door frame 2, as shown in Fig. 1.

The door frame 2 has the usual door 3 hinged thereto.

A bas 4: has apertures 5 adjacent each end thereof for receiving screws 6 or like fasteners for securing the base 4.- to the door frame 2. The base 4: is constructed from a single length of metal, which is bent in substantially U-shaped formation as shown at 7 adjacent one end and the arm portions of which are apertured to receive a cartridge 8. This cartridge 8 may be of any desired caliber and is of the blank construction or a cartridge eliminating the use of the bullet. The base 4: is bent upon itself to form a pair of relatively spaced supports 9, which are apertured to receive a rod 10, one end of which has formed thereon a head 11 adapted to engage the cartridge to fire the same. A portion of the base between the support 9 is struck up to form a catch 12 adapted to be engaged by a lug 13 carried by the rod 10 to hold the rod 10 in a set position or a position so that the head 11 is adjacent one of the supports 9 and at a point remote from the cartridge 8. A coiled spring 14 is mounted upon the rod 10 and is interposed between th lug l3 and one of the'supports 9 and is adapted to be compressed when the rod 10 is drawn rearwardly to engage the lug 13 against the catch 12 to hold said rod in a set position.

. An arm 15 is pivoted to the free end of the rod 10 as shown at 16 and is adapted to be swung upon its pivot to overlie the door 3 as shown in Fig. 1 when the rod 10 is in a set position, whereby upon opening the door 3, the door engages the arm 15 partly rotating the rod 10 to disengage the lug 13 from the catch 12 permitting the spring 1 1 to expand and drive the head 11 against the cartridge to fire the same, thus giving an alarm that the door 3 is being opened.

While I have shown and described the preferred embodiment of my invention, it Will be understood that minor changes in construction, combination and arrangement of parts may be made Without departing from the spirit and scope of the invention as claimed.

What is claimed is:

A burglar alarm comprising an elongated metallic base adapted to hav each end secured to a door frame, said base being bent upon itself at spaced points to form relative spaced supports and having openings therein, an angularly related tongue struck up from the base between said supports, a rod slidable in the openings of said sup ports and having a head formed on one end thereof, an arm pivoted to the other end of the rod and adapted to be swung into the Copies of this patent may be obtained for five cents each, by addressing the path of a door, a pin formedon said rod between the supports and adapted to engage the tongue to hold the rod retracted, a spring mounted on said rod and bearing against one of the supports and the pin, said base being bent upon itself adjacent one end and in spaced relation to one of said supports to form a substantially U-shaped member having its arms provided With apertures to receive a cartridge so as to support the same in the path of the head and to be set-off by the same when the rod is freed by the door. In testimony whereof I affix my signature in presence of tWo Witnesses.

CHARLES DE STEFANO. Witnesses: v r

J OHN J. Ron, FANNIE C. OVER'I'ON.

Commissioner of Patents,

Washington, D. 0. 

